The present invention relates to a connection cable apparatus for connecting between a robot and a controls device.
Generally, an industrial robot is installed on the floor. The signal wire for controlling the robot is called the connection cable, and includes the following types.
1) A composite cable containing plural wires in one sheath.
2) A cable with a connector attached by terminating cable ends having wires passed through a flexible tube.
These connection cables are disposed at non-moving parts in the lower part of the robot main body at the opposite side of the connector. Further by mutually coupling the connection cable: connector section and the receiving side connector section provided at the lower part of the robot main body, the signal from the control device is transmitted to the robot.
FIG. 18 shows a case of mounting a robot on a platform. The connection cable designed to be laid on the floor is used in such state of installation as shown in FIG. 18. The connection cable of straight connection type sags due to gravity.
Mainly, herein, the signal and power for controlling the servo motor of the robot main body are exchanged between the robot main body and control device through a harness called the connection cable bundling the signal wires and the power wires.
The connection section is separable by the connector. Signal wires of each harness are terminated, and soldered or crimped to the connector terminal, and inserted into the connector section main body.
The cable lock section fixes the harness at the cable lock section of the connector as follows.
i) When the harness is composed of bulk wires, the flexible tube through which the bulk wires are passed is fixed.
ii) When the harness is composed of composite cables, the armor of the composite cable is fixed.
In the following cases, the connector section of the connection cable might be broken, or the harness inside the connector might be disconnected.
i) If the user""s foot catches the connection cable.
ii) If the user operates the robot by mistake while teaching the robot, and the end effector of the robot catches the connection cable main body.
Besides, when the robot main body is installed on the platform as shown in FIG. 18, the harness may be broken in the connector of the connection cable due to weight of connection cable or aging effects.
Accordingly, as a conventional method of protecting the connection cable, FIG. 19 shows a method disclosed, for example, in Japanese Laid-open Patent No. 6-187835.
In a joint cable 111 in FIG. 19, a reinforcing member 112 is supporting the weight of an underwater working machine. In this structure, therefore, tension does -not work on the connection cable.
If necessary to replace the connection cable during underwater work, this joint cable is replaced.
In the case of a floor-mount robot, the connection cable for linking between the robot and control device is laid down horizontally on the floor. Further, the connection cable is connected to the non-moving part of the robot. Therefore, nothing has been considered about its impact resistance.
At the time of teaching or maintenance of the robot, the operator often used to drag and pull the connection cable by himself or by a crane or a tool. The connection cable was sometimes damaged. Its effect was seen in the connector section at the junction of the robot main body lower part and the connection cable. Besides, when the robot is mounted on the platform as shown in FIG. 18, the connection cable sags by its own weight in the gravity direction. Therefore, strands of composite cable are pulled in the gravity direction. In the case of a tube, the wires in the tube are pulled in the gravity direction.
In addition, in both cases above, a stress is also applied due to the difference in the bending major diameter and bending minor diameter of the connection cable. As a result, a force larger than the specified value is applied on the pin of the connector.
When it is known beforehand that the robot is installed on a platform as shown in FIG. 18, an angle connector may be used as the connector section of the connection cable, so that the connection connector section and connection cable may be connected straightly. In this case, too, an eccentric load is applied on the connection cable connector section.
Besides, when the connection cable is caught, inevitably, an impact was applied on the connector section at the junction of the robot main body lower part and the connection cable.
In the case of angle connector type, it is mainly out of the standard product. It hence has effects on the cost and term of delivery.
In the case of FIG. 19, a connection cable 113 is laid along a reinforcing member 112, and is fixed to the reinforcing member 112 at plural positions by means of a bundling tool 125. At the connection end side to the underwater working machine, the connection cable 113 is inserted into a flexible tube 126 together with the reinforcing member 112, and is drawn outside through a hole penetrating through a coupling tool 116.
Connectors 121 are provided at both ends of the connection cable 113. Each connector 121 is connected to a connector 106 of a core 105 drawn out from a tether cable 102 and a connector o f the underwater working machine.
Through a joint cable 111 thus composed, the tether cable 102 and underwater working machine are connected as shown in FIG. 19. While the underwater working machine is working, in the joint cable 111, the weight of the underwater working machine is supported by the reinforcing member 112. Therefore, no tension acts on the connection cable 113.
If the joint cable 111 is damaged during the underwater work, the tether cable 102 is hoisted by the winch of the mother vessel, and the joint cable 111 and underwater working machine are lifted onto the mother vessel. By removing bolts 119, 123 of coupler 115 and coupling tool 116 of the joint cable 111, coupling of the reinforcing member 112, tether cable 102, and underwater working machine is cleared. The connectors 121 at both ends of the connection cable 113 are separated from the tether cable 102 and each connector of the underwater working machine.
Consequently, by a new joint cable 111, the tether cable 102 and underwater working machine are coupled. Again, the underwater working machine is put back into the water, and the operation is resumed.
That is, as for the cables, spare:joint cables 111 are prepared on the mother vessel. If necessary to replace the connection cable during underwater work, only the joint cable 111 is replaced.
Such exchange of connection cable is, however, difficult in the industrial robot. This is because the industrial robot is installed in a place of a complicated layout of machines and devices in the manufacturing line.
It is hence an object of the invention to protect the connection cable of the robot compactly.
1) A connection cable apparatus between a robot manipulator and its control device of the invention comprises connection units of a manipulator and a connection cable, and a reinforcement plate, in which the connection cable is fixed by using the reinforcement plate so that the connection cable may be firmly fixed.
2) A connection cable apparatus of the invention comprises connection units of a robot manipulator and a connection cable, and an angle box, in which the angle box stands between connection units, so that the drawing direction of the connection cable may be varied.
3) A connection cable apparatus of the invention comprises plural wires including a signal wire and a power wire, and a connection processing section of terminals of plural wires. In the connection processing section, the length of the wire having the smaller sectional area of the plural wires is longer than the length of the wire having the wider sectional area. Dividing these wires in groups, it is intended to prevent effects of stress due to difference between the bending major diameter and bending minor diameter of the connection cable.
Thus the invention presents a connection cable apparatus capable of protecting connection cable and connector section.